Bsf Block 2: Autonomic Nervous System 2 (Nissanov)

Front 1

T or F. The general visceral afferent (GVA) system is considered part of the autonomic nervous system.

Back 1

False. It is classically not considered part of the ANS but is essential for normal autonomic functions and reflexes

Front 2

Nociceptors are the viscerosensory receptors for _________.

Back 2

pain. They respond to stimuli that has damaging potential to tissue or to stimuli that results from already damaged tissue (noxious stimuli)

Front 3

Nociceptors in viscera are free ending (myleinated/unmyelinated) small-diameter axons.

Back 3

unmyelinated

Front 4

Mechanoreceptors, baroreceptors, chemoreceptors, osmoreceptors and internal thermal receptors are all classified as...

Back 4

physiological receptors (they respond to innocuous stimuli and monitor visceral function)

Front 5

What physiological receptor detects movement, stretch, tension or pressure (responsible for the sense of fullness in the bladder)?

Back 5

mechanoreceptor

Front 6

What physiological receptors monitor blood pressure and are found in the walls of the aortic arch and carotid sinus?

Back 6

baroreceptors

Front 7

What physiological receptors monitor blood chemistry (changes in arterial oxygen and carbon dioxide, blood pH, and to some drugs), and are found near baroreceptors in structures called carotid and aortic bodies, and in the hypothalamus?

Back 7

chemoreceptors

Front 8

What physiological receptors monitor blood osmolarity and are found in the hypothalamus?

Back 8

osmoreceptors

Front 9

What physiological receptors monitor blood temperature and are found in the hypothalamus?

Back 9

thermoreceptors

Front 10

_______________ are transducers that convert mechanical distention into nerve action potentials.

Back 10

Mechanoreceptors

Front 11

What kind of receptor is the heart stretch-gated channel (SAC)?

Back 11

mechanoreceptor

Front 12

GVA tend to dominate (parasympathetic/sympathetic) nerves and are sparse in (parasympathetic/sympathetic).

Back 12

-Dominate parasympathetic nerves (80% of vagus axons)
-Sparse in sympathetic nerves (20% of greater splanchnic nerve)

Front 13

Axons of nociceptors are carried almost exclusively by ____________ nerves while physiological receptors project via _____________ nerves.

Back 13

-nociceptors: sympathetic nerves
-physiological receptors: parasympathetic nerves

Front 14

GVA and somatic (GSA) cell bodies are found in either __________ or __________.

Back 14

dorsal root ganglia OR
cranial nerve ganglia

Front 15

Nociceptor fibers travel along sympathetic nerves through ganglia?

Back 15

prevertebral or paravertebral (chain/trunk) ganglia (NOTE: fibers DO NOT synapse here...they continue on to synapse later in the spinal cord once they pass their cell bodies in the dorsal root ganglia)

Front 16

Once nociceptor input reaches the sympathetic trunk, it may travel through the _________ ramus of spinal nerves to reach the dorsal root ganglion, where its cell body is located (NOTE: it does not synapse at the dorsal root ganglion).

Back 16

white

Front 17

In what spinal cord segments do nociceptors GVA fibers synapse?

Back 17

Nociceptor GVA fibers travel via sympathetic nerve pathways, so they terminate/synapse at the thoracolumbar (T1 to L2) spinal segments in lamina I, V, VII or VIII.

Can also terminate on GVE cells in the IML (intermediolateral column), providing a synapse reflex arc

Front 18

Second order GVA fibers convey information to the contralateral side of the spinal cord's gray matter via the _______________ system or bilaterally via the ___________________.

Back 18

contralateral: anterolateral system
bilateral: via spinoreticular fibers that ascend to the brain

Front 19

When stomach pain is perceived as epigastric pain (above the stomach), this is referred to as....

Back 19

referred pain

Front 20

Referred pain is due to the convergence of what signals?

Back 20

GVA (visceral sensory) and GSA (somatic sensory) of visceral and somatic structures whose afferents enter the dorsal horn of the spinal cord via the same dorsal root

Front 21

The referred pain arising from heart disease, perceived as a squeezing sensation originating from behind the sternum and sometimes radiating down the left arm, is called...

Back 21

angina

Front 22

Non-noxious or physiological stimuli is conducted through the (sympathetic/parasympathetic) division.

Back 22

parasympathetic (craniosacral--S2 to S4 and CN VII, IX, and X)

Front 23

What are the 2 cranial nerves that carry the most significant amounts of parasympathetic afferents?

Back 23

CN IX (glossopharyngeal) and X (vagus)

Front 24

Afferents of chemoreceptors of the carotid body and baroreceptors of the carotid sinus travel through which nerve?

Back 24

CN IX (glossopharyngeal)

Front 25

Parasympathetic afferents of nonciception and touch from palatine-tonsil area (the basis of the gag-reflex) travel through what nerve?

Back 25

CN IX (glossopharyngeal). NOTE: noxious (nociceptive) stimuli usually travels through sympathetic pathways. This is an exception

Front 26

Parasympathetic afferents traveling through CN IX (glossopharyngeal) have cell bodies located where?

Back 26

INFERIOR glossopharyngeal ganglion

Front 27

Parasympathetic afferents of CN X (vagus nerve) transmit a wide variety of physiologic information from what parts of the body?

Back 27

thoracic viscera and all abdominal viscera above the splenic flexure of the colon

Front 28

The vasovagal reflex begins with distension in the stomach, which stimulates the secretion of stomach glands. Which nerve carries the afferent input of the vasovagal reflex?

Back 28

CN X (vagus nerve)

Front 29

Physiological afferents in the aortic arch are carried through which nerve?

Back 29

CN X (vagus nerve)

Front 30

Parasympathetic afferents traveling through CN X (vagal) have cell bodies located where?

Back 30

INFERIOR vagal ganglion

Front 31

Special visceral afferents (SVA) for taste, traveling through CN X (vagal), have cell bodies located where?

Back 31

also in the inferior vagal ganglion

Front 32

Parasympathetic afferents traveling through S2 to S4 have cell bodies located where?

Back 32

in dorsal root ganglia. Recurrent fibers enter through the ventral root

Front 33

Parasympathetic afferents that enter the spinal cord via the ventral root are called...

Back 33

recurrent fibers

Front 34

Parasympathetic afferents terminate/synapse where in the spinal cord?

Back 34

posterior horn. From here they can they can interact with preganglionic motor neurons (thereby forming reflex arcs) or ascend to higher centers (hypothalamus)

Front 35

Emptying of the urinary bladder is called...

Back 35

Micturition

Front 36

The external sphincter of the urethra is normally ____________ (relaxed/contracted).

Back 36

contracted

Front 37

Micturition: As the bladder fills, stretch receptors fire action potentials that project via the pelvic nerve and enter the spinal cord through the ___________ root.

Back 37

ventral

Front 38

Micturition: Once in the spinal cord, preganglionic (parasympathetic/sympathetic) action potentials return to the bladder and external sphincter of the urethra via a ____________ pathway, causing the bladder to contract and the external sphincter of the urethra to relax...enabling micturition.

Back 38

-parasympathetic
-disynaptic

Front 39

If a person stands up quickly, the body's failure to compensate for the sudden change in blood pressure results in...

Back 39

orthostatic hypotension

Front 40

Standing up quickly (induces/reduces) baroreceptor activity.

Back 40

reduces baroreceptor output to CN IX and X

Front 41

Reduced baroreceptor activity, as a result of standing up quickly, reduces the output of what two neurons? What are their functions?

Back 41

-vagal motor neuron (has preganglionic parasympathetic cells that normally decrease cardiac rate and output. When baroreceptor activity is reduced, cardiac rate and output increase).

-vasopressor medullary neurons (these sympathetic cells have pacemaker activity that is normally inhibited. Reduced baroreceptor activity disinhibits them, causing sympathetic stimulation that increases heart rate, cardiac output, as well as vasoconstriction in skeletal muscle and abdominal visceral organs.

Together, the inhibition of vagal motor neurons and vasopressor medullary neurons serves to increase blood pressure, counteracting orthostatic hypotension.

Front 42

PO2 & PCO2 is assessed by chemoreceptors in the _________________. Afferents are conveyed via __________.

Back 42

-chemoreceptors in aortic and carotid bodies
-afferents conveyed via CN IX and X

Front 43

Low PO2, as assessed by chemoreceptors in aortic and carotid bodies, leads to ___________________.

Back 43

tachycardia and increased vascular tone, shunting more O2 to the brain